Lock your door. This is the single most important way to keep your computers secure. "I don't want to simplify this too much, but I've seen so much of this kind of crime where the unfortunate victim just leaves his door unlocked," says Antinozzi. "Lock your door." Mark the property in a very visible, permanent way. Just as would-be thieves are often deterred by homes bearing "Protected by ..." signs, so is the computer thief going to go for an unmarked laptop. Forget high-tech hacking.

One new credit card scam relies more on X-Acto knives and glue sticks than wi-fi and laptops, but helps criminals steal your money just the same. Shaving is a low-tech form of card theft where thieves sort through sets of 16-digit numbers to find one that matches an existing card, and then verifying that number either by trying to make a purchase online or by phone. The scammers can also buy a list of valid credit card numbers from black market sites online.

Once they have their hands on a valid account number, they then create a new card with those numbers by shaving the numbers off of gift cards or expired credit cards and gluing them onto a defunct or stolen card. The magnetic strip is gouged with a knife or pen so that a store clerk has to manually enter the account number on a keypad, and the charge goes through. Another way consumers can fight shaving is with a credit card account that generates a new number for every new transaction.

Citibank offers Virtual Account Numbers to cardholders for online purchases while PayPal provides the Secure Card in the form of a MasterCard debit card. While these can only be used online, Qsecure is rolling out a SmartStripe credit and debit card that looks like any other card.

However, a chip embedded in the card's magnetic stripe automatically generates a different number for each purchase. Don't assume your desktop computer is safe. Invest in some inexpensive cables designed to tether the CPU to something immovable in the room.